Electronically presented content items, such as video games and other media items, may often present a virtual area, which may also sometimes be referred to as a virtual world, in which various actions may be performed. In some examples, a content item may improve the user experience by making its virtual area appear to be more realistic and/or life-like, such as by increasing the complexity and level of detail of the virtual area. Unfortunately, however, increasing the complexity of a virtual area may substantially increase the time, effort, and resources required to create, present, maintain and modify the virtual area. In some examples, a virtual area may be made more interesting to users by including various different types of terrain, such as flat and/or buildable space, mountains, valleys, berms (e.g., cliffs), rivers, lakes, oceans, deserts, forests, and many others. The terrain may be populated by various objects, such as trees, bushes, rocks, snow, grass, fish, birds, animals, people, vehicles, buildings, and many others.
Some conventional content development techniques may require certain types of terrain and/or objects to be manually positioned and inserted into a virtual area, which, particularly for larger and more detailed areas, may be a highly time consuming process. Moreover, modifications to areas of terrain and/or populated objects in an executing content item may sometimes require the content item to be stopped and restarted, thereby interrupting and degrading the user experience. Another way in which some virtual areas may appear life-like is by including different times of day (e.g., morning, daytime, night), different seasons (e.g., summer and winter), and different weather conditions (e.g., sun, rain and snow). However, the transitions between these seasons and weather conditions may often appear unnatural to users. For example, an area may transition directly from the middle of winter to the middle of summer. This may result in unexpected behaviors, such as trees changing directly from having no leaves to having fully grown leaves.